漳卫南运河流域水质时空变化特征及其污染源识别

采用聚类分析、季节性Kendall法分析了漳卫南运河流域的水质时空演变特征及水质变化趋势,采用因子分析/主成分分析法和多元回归分析法定性识别了流域水质污染的主要污染源并对其贡献率进行了计算.空间聚类和站点因子得分计算后发现,漳卫南运河流域水质空间上可以分为两大类,一类是位于流域西北部漳河中上游区域,该区域水质优良;第二类为卫河流域及漳卫南运河东部平原区,该区域水体受污染严重,水质较差,且沿途接纳点源排放口排入的污染物,水质空间变化较大.时间聚类和季节性Kendall趋势分析表明:流域水质在2002～2009年间可分为3个阶段2种变化趋势,2002～2003年为水质恶化阶段,卫河及漳卫南运河东部平原区干流水质严重污染,漳河上游及中游岳城水库水质也呈恶化趋势,但总体水质良好;2004～2006年为水质好转期,2007～2009年为第三阶段,水质进一步好转期.在2004～2009年间,流域整体水质虽然好转,但西南部的卫河流域及漳卫南运河东部平原干流区水环境状况依然堪忧.因子分析/主成分分析和多元线性回归分析结果表明,造成漳卫南运河流域水质污染的污染物主要来源于市政污水、重工业废水、化学工业废水、天然污染源和采矿活动,汛期农业生产引起的农业非点源排放以及暴雨径流引起的非点源排放也占相当比例.采用主成分多元线性回归方法评价了各种污染源的贡献率.结果可以为漳卫南运河流域水污染控制战略制定提供有益的参考.

Spatiotemporal Variation Analysis and Identification of Water Pollution Sources in the Zhangweinan River Basin

In this study, several statistical methods including cluster analysis, seasonal Kendall test, factor analysis/principal component analysis and principal component regression were used to evaluate the spatiotemporal variation of water quality and identify the sources of water pollution in the Zhangweinan River basin. Results of spatial cluster analysis and principal component analysis indicated that the Zhangweinan River basin can be classified into two regions. One is the Zhang River upstream located in the northwest of the Zhangweinan River basin where water quality is good. The other one covers the Wei River and eastern plain of the Zhangweinan River basin, where water is seriously polluted. In this region, pollutants from point sources flow into the river and the water quality changes greatly. Results of temporal cluster analysis and seasonal Kendall test indicated that the study periods may be classified into three periods and two different trends were detected during the period of 2002-2009. The first period was the year of 2002-2003, during which water quality had deteriorated and serious pollution was observed in the Wei river basin and eastern plain of the Zhangweinan River basin. The second period was the year of 2004-2006, during which water quality became better. The year of 2007-2009 is the third period, during which water quality had been improved greatly. Despite that water quality in the Zhangweinan River basin had been improved during the period of 2004-2009, the water quality in the Wei River (southwestern part of the basin), the Wei Canal River and the Zhangweixin River (eastern plain of the basin) is still poor. Principal component analysis and multi-linear regression of the absolute principal component scores showed that the main pollutants of the Zhangweinan River basin came from point source discharge such as heavy industrial wastewater, municipal sewage, chemical industries wasterwater and mine drainage in upstream. Non-point source pollution such as agricultural pollution and runoff pollution caused by heavy rainfalls also showed considerable impact on water quality in the Zhangweinan River basin during flood seasons. These results provide useful information for better pollution control strategies in the Zhangweinan River basin.